Cleanup kAlignSurfaceLayerImplToPixelGrid

This feature has launched and we can clean up the code.

scaled-oopif-text-not-blurry.html and
translated-oopif-text-not-blurry.html had bugs which caused them to
fail. These tests have been updated to work. I verified the updated
tests fail with the kAlignSurfaceLayerImplToPixelGrid feature disabled.

The in-process scrollbar expectations on MacOS seem incorrect and these
tests have been marked as failing on that platform.

Fixed: 442383400, 359279545
Change-Id: I2aa6632f140e69510a92f99658540ff7db51fa15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6937205
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1514367}